Metallurgic ceramics as a key to Viking Age workshop organisation

Abstract

Metallurgic ceramics form a common group of Iron Age/Early Medieval workshop finds. These highly specialized refractory ceramics carry a lot of information; telling us not just about the blacksmiths’ and goldsmiths’ skills in handling ceramic materials, but also about production and workshop organisation. This paper mainly deals with the question of heating trays, interpreted as vessels used in fire assay, or the refining and analysis of silver. A general connection between assaying and means of payment is briefly discussed, and a hypothesis is put forward that the presence of heating trays may provide information on Viking control over the means of payment and trade, in the same way as the presence of weights and weighing does. The Viking weight economy was dependent on methods for weighing the silver used for payment and methods for checking its purity. Analyses of heating trays from 9th–10th century Birka and of trays from the 10th–11th century mint in Sigtuna are made and an experimentally produced heating tray is analysed for comparison purposes.